1. Field of the Invention
This application relates to a microfluidic biosensing system, and more particularly, to a microfluidic biosensing system using the Raman barcode bead to sense the specific target bioparticle.
2. Description of the Related Art
When biological particles such as bacteria, viruses, cells, particles, and so on in a fluid are detected, the conventional methods often use a fluorescent label to detect the fluorescence intensity thereof. That is to say, the fluorescent label is irradiated by light after it is attached to the target bioparticle in order to confirm the presence of the target bioparticle. Because different fluorescent labels have different spectra, the fluorescent signal has been widely used in the optical barcode and the spectral labeling system. In fact, the fluorescent labels are of a wider application. For example, the fluorescent labels can be applied to the biotechnology, such as the deoxyribonucleic acid (DNA) sequencing, the DNA microarray and the fluorescent probes for the specific ions within living cells, in order to observe the physiological state, the activity, and so on of the cell.
However, after cycles of repeated exposure, the fluorescent label may encounter the technical problem such as the photo-bleaching in sensing. That is, a fluorescent label may be damaged after repeated exposure, resulting in the observation difficulties. Peak overlapping is another serious problem in terms of the fluorescent label, which leads to the errors in the observation due to the difficulties of distinguishing different fluorescent signals from each other. In addition, the fluorescent labels require a variety of excitation lights when applied to a multiplex sensing stage, so that the complexity of the whole system is raised and the increase of the overall costs becomes inevitable.
Generally, the traditional detection methods have low sensing sensitivity, need a large volume of sample, or require complex culture and testing procedures. Beside, in order to meet the requirement, the detection process often has to be performed in a particular laboratory, and usually takes a few days to weeks. As a result, the traditional detection method cannot satisfy the need for immediate multiplex detection or rapid on-site detection.